This project extends empirical work on a strong regularity in recognition memory, the mirror effects, and theoretical work designed to account for that regularity. The theoretical and empirical work led to the establishment of two further regularities -- the symmetrical movement of underlying (signal and noise) distributions when memory is impaired (as with forgetting) or facilitated (as with additional study time); and the order of the slopes of the receiver operating characteristics for conditions that differ in recognition efficiency. The proposed work will examine the following: 1. Extension of the work to cover a complete ordering of slopes of receiver operating characteristics as a function of accuracy of recognition. The order of slopes as a function of accuracy of recognition memory involves critical issues for a number of the current global theories of memory. 2. Further exploration of variables affecting the bilateral movement of underlying distributions - noise level, efficiency of encoding, proactive interference. 3. Extension of attention/likelihood theory to more complex situations in which the subject's model of the situation differs from the actual situation. 4. Demonstration that the theory predicts a fourth regularity, the absence of list-strength effects. Those effects involve the use of mixed lists, lists in which the subjects get different numbers of trials or different study times for various items. The absence of the list strength effect is important since it is again critical for a number of current models of memory. The absence of the list strength effect will be further examined in new experimental arrangements that generalize it -- forgetting and proactive interference. A fifth regularity, the identity of receiver operating characteristic slopes, which can also be derived from the theory, will be tested in the planned experiments. GANT=R01MH45137 Pavlovian conditioning researchers have displayed renewed interest in associations formed between two sensory events. Pairing of sensory events is also a central feature of a perceptual phenomenon described by McCollough in 1965, now known as the McCollough effect (ME). The proposed research is designed to integrate these two research traditions. The ME is demonstrated by presenting two chromatic grids during an "induction" period (e.g., a grid of black and green horizontal bars alternating with a grid of black and magenta vertical bars). Subsequently, complementary color aftereffects contingent on bar orientation are noted on an achromatic grid. For the above example, the white space between black horizontal bars appears pink and the white space between black vertical bars appears green. The ME is one of a category of contingent color aftereffects (CCAEs). The proposed research has two major objectives: (1) to evaluate the extent to which CCAEs, which result from pairing of color with another feature of the stimulus, can be understood as an instance of another well-studied phenomenon of pairing, Pavlovian conditioning, and (2) to study a new CCAE: illusory color seen on achromatic words following exposure to these words in color. In all experiments, a computer system is used for induction and assessment of CCAEs. Standard psychophysical procedures, appropriately modified for the task, are used to objectively assess aftereffect magnitude. The research concerning the contribution of Pavlovian conditioning to the CCAE will aid in understanding the contribution of learning to perception. Research addressed to the role of learning in the CCAE is also relevant to the role of learning in homeostatic functioning. Many conditioning phenomena typically studied with animals have been demonstrated with CCAEs, thus the research provides learning researchers with a valuable, inexpensive alternative to the use of animals. The research concerning the word-CCAE many aid in understanding how people code and process the written word. In addition, it is likely that the word-CCAE research is relevant to reports of troublesome contingent color aftereffects suffered by computer operators. These aftereffects have been implicated in ophthalmologic, psychiatric, and other work- related problems of computer operators.